JP4695513B2 - Process for producing release film - Google Patents

Description

  The present invention relates to a release film and a manufacturing method thereof. More specifically, the present invention relates to a release film having a release agent layer on one side of a base film and an antistatic layer on the back side thereof, which has both an excellent antistatic function and a release function, and a method for producing the release film. It is about.

Release films are used as cast film-forming process films such as polyurethane resins, polyacrylic resins, and polyvinyl chloride resins, green film-forming process films for multilayer ceramic capacitors, and protective films for adhesives in adhesive products. .
In this release film, a layer made of a release agent such as a silicone resin, a long-chain alkyl group-containing compound that is a non-silicone resin, or an olefin resin is generally formed on the surface of a base film. After such a release film is used for the above application, charging occurs when the release film is peeled off, which leads to an undesirable situation in which foreign matter adheres to the product.
In order to cope with such an unfavorable situation, an antistatic treatment is performed on the release film.
Conventionally, ionic compounds such as quaternary ammonium salts have been frequently used for antistatic treatment of release films. However, when this ionic compound is used in the antistatic layer, its antistatic performance is greatly affected by moisture in the atmosphere.
Moreover, although the system which disperse | distributed electroconductive metal type fillers, such as a metal and a metal oxide, to binder resin is also proposed, a particle diameter is large in this case, and there exists a possibility that the smoothness of a film may be impaired.
On the other hand, recently, an antistatic layer in which a conductive polymer compound such as polythiophene is dispersed in a binder resin has been proposed (see, for example, Patent Document 1).
However, since it is difficult to uniformly disperse the conductive polymer compound in the binder resin, the antistatic property becomes unstable, and a large amount of addition is required to develop a stable antistatic performance. The cost is inevitable. Further, when the antistatic performance is stabilized by increasing the coating amount, blocking may occur due to an increase in the thickness of the antistatic layer.
Japanese Patent Application Laid-Open No. 2002-179954

  Under such circumstances, the present invention is a release film having an excellent antistatic function and a release function, and the smoothness of the film is not impaired, and the thickness of the antistatic layer is compared. The purpose of the present invention is to provide a release film that is thin and has stable antistatic performance.

As a result of intensive studies to develop a release film having the above-mentioned preferable properties, the present inventors have a release agent layer on one side of the base film and carbon nanofibers or carbon on the other side. It has been found that a release film having an antistatic layer made of a cured product of an active energy ray-curable resin composition containing nanofibers and a conductive polymer compound can meet the purpose, and the present invention is based on this finding. It came to complete.
That is, the present invention
(1) a carbon nanofiber having an average length of 0.8 to 15 μm and an average outer diameter of 1 to 100 nm, a conductive polymer compound, and an ultraviolet polymerizable monomer or oligomer having two or more polymerizable unsaturated groups in the molecule; A coating liquid I containing a photoinitiator was prepared, and separately, a coating liquid II containing a silicone release agent obtained by adding a crosslinking agent and a catalyst to a thermosetting silicone resin was prepared, The coating liquid I is applied to the surface, dried, and then the coating film is irradiated with ultraviolet rays to be cured, and the content of carbon nanofibers in the cured product is 0.1 to 30% by mass and cured. While forming an antistatic layer having a thickness of 0.01 to 3 μm in which the content of the conductive polymer compound in the product is 0.01 to 10% by mass, the coating liquid II is formed on the other surface, as in terms of solid content coating amount, after coating with 0.01 to 3 g / m ^2, heating After heat treatment at degrees 50 to 120 ° C., a method of manufacturing a release film ultraviolet was irradiated with a thickness of, and forming a release agent layer of 0.01 to 3 [mu] m,
(2) The method for producing a release film according to the above (1), wherein the thermosetting silicone resin is polydimethylsiloxane having a vinyl group or a hexenyl group as a functional group,
(3) a carbon nanofiber having an average length of 0.8 to 15 μm and an average outer diameter of 1 to 100 nm, a conductive polymer compound, and an ultraviolet polymerizable monomer or oligomer having two or more polymerizable unsaturated groups in the molecule; A coating liquid I containing a photoinitiator is prepared, and separately, one or more release agents and crosslinking agents selected from alkyd resin release agents, long-chain alkyl group-containing compound release agents, and acrylic resin release agents Is prepared at a mass ratio of 70:30 to 10:90, the coating liquid I is applied to one surface of the base film, dried, and then the coating film is irradiated with ultraviolet rays. The thickness of the carbon nanofiber in the cured product is 0.1 to 30% by mass, and the content of the conductive polymer compound in the cured product is 0.01 to 10% by mass. When an antistatic layer having a thickness of 0.01 to 3 μm is formed, In addition, after the coating liquid II is applied to the other surface, heat treatment is performed to form a release agent layer having a thickness of 0.01 to 3 μm,
( 4 ) Conductive polymer compounds are polyacetylene, polythiophene, polyaniline, polypyrrole, poly (phenylene vinylene), poly (vinylene sulfide), poly (p-phenylene sulfide) and poly (thienylene vinylene). 10) The method for producing a release film according to any one of the above items (1) to (3) , which is at least one selected from the group of compounds, and ( 5 ) the surface resistivity of the antistatic layer is 10 method for producing a release film according to any one of ¹⁰ Omega / □ or less is the above (1) to (4) of this section,
Is to provide.

  According to the present invention, there is provided a release film having a release agent layer on one side of a base film and an antistatic layer on the back side thereof, which has an excellent antistatic function and a release function. In addition, it is possible to provide a release film that does not impair the property, has a relatively thin antistatic layer, and has stable antistatic performance.

The release film of the present invention is a release film having a release agent layer on one side of the base film and an antistatic layer on the opposite side.
There is no restriction | limiting in particular in the base film used for the peeling film of this invention, It selects suitably from what was conventionally used as a base film of a peeling film according to the use of this peeling film. Examples of such a base film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene films, polypropylene films, polyvinyl chloride films, polyvinylidene chloride films, polyvinyl alcohol films, and ethylene-vinyl acetate. Copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyethersulfone film, polyphenylene sulfide film, polyetherimide film, polyimide film, fluororesin film, polyamide film, acrylic Resin film, norbornene resin film, cycloolefin It can be mentioned fat film.
There is no restriction | limiting in particular in the thickness of this base film, Although it selects suitably according to the use of a peeling film, it is 10-150 micrometers normally, Preferably it is 20-120 micrometers.
In addition, this base film is surface-treated by an oxidation method, a concavo-convex method, or the like on one or both sides as desired for the purpose of improving the adhesion between the release agent layer and the antistatic layer provided on the surface. Processing can be performed. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like. Examples include solvent processing methods. These surface treatment methods are appropriately selected according to the type of the base film, but generally, the corona discharge treatment method is preferably used from the viewpoints of effects and operability.

In the present invention, a release agent layer is provided on one surface of the base film. As the release agent constituting the release agent, a silicone release agent or a non-silicone release agent is used. These release agents are appropriately selected according to the use of the release film.
As the silicone release agent, an addition reaction type silicone release agent is preferable, and this addition reaction type silicone release agent is obtained by adding a crosslinking agent and a catalyst to a main agent composed of an addition reaction type silicone resin. Further, if desired, an addition reaction inhibitor, a release adjusting agent, an adhesion improving agent and the like may be added. Moreover, when performing ultraviolet irradiation other than a heat | fever in the hardening process after application | coating of a release agent, you may add a photoinitiator.
As the type of silicone release agent, as long as it is an addition reaction type, its form may be any of a solvent type, an emulsion type and a solventless type, but the solvent type is most suitable in terms of quality and ease of handling.
The addition reaction type silicone resin is not particularly limited, and those conventionally used as conventional thermosetting addition reaction type silicone resin release agents can be used. For example, polyorgano having alkenyl group as a functional group in the molecule. The at least 1 sort (s) chosen from siloxane can be mentioned. Preferred examples of the polyorganosiloxane having an alkenyl group as a functional group in the molecule include polydimethylsiloxane having a vinyl group as a functional group, polydimethylsiloxane having a hexenyl group as a functional group, and a mixture thereof. .
Examples of the crosslinking agent include polyorganosiloxane having at least two silicon-bonded hydrogen atoms in one molecule, specifically, a dimethylhydrogensiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy. Examples thereof include a group-end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group-end-capped poly (methylhydrogensiloxane), and poly (hydrogensilsesquioxane). The usage-amount of a crosslinking agent is normally selected in the range of 0.1-100 mass parts with respect to 100 mass parts of addition reaction type silicone resins, Preferably it is 0.3-50 mass parts.
As the catalyst, a platinum compound is usually used. Examples of the platinum compound include fine platinum, fine platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, palladium, rhodium catalyst, and the like. . The usage-amount of a catalyst is about 1-1000 ppm as a platinum-type metal with respect to the total amount of an addition reaction type silicone resin and a crosslinking agent.

Examples of the release adjusting agent include polyorganosiloxane having no alkenyl group and hydrogen atom bonded to a silicon atom in the molecule, specifically, trimethylsiloxy group end-capped polydimethylsiloxane, dimethylphenylsiloxy group end-capped polydimethylsiloxane. And silicone resins.
The addition reaction inhibitor is a component used to impart storage stability to the composition at room temperature, and specific examples thereof include 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1 -Penten-3-ol, 3-methyl-3-penten-1-in, 3,5-dimethyl-3-hexen-1-in, tetravinylsiloxane cyclic, benzotriazole and the like.
Examples of the adhesion improver include vinyltriacetoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-methacryloxypropyltrimethoxysilane.
There is no restriction | limiting in particular as a photoinitiator, Arbitrary things can be suitably selected and used from what is conventionally used for the ultraviolet curable resin. Examples of the photoinitiator include benzoins, benzophenones, acetophenones, α-hydroxy ketones, α-amino ketones, α-diketones, α-diketone dialkyl acetals, anthraquinones, thioxanthones, and other compounds. Can be mentioned.
These photoinitiators may be used independently and may be used in combination of 2 or more type. Moreover, the usage-amount is normally selected in the range of 0.01-30 mass parts with respect to 100 mass parts of total amounts of the said addition reaction type silicone resin and a crosslinking agent, Preferably it is 0.05-20 mass parts.

In order to form a release agent layer composed of the silicone release agent on one surface of the base film, first, a solvent type silicone release agent coating solution or an emulsion type silicone release agent coating solution is prepared. .
In the solvent type silicone release agent coating solution, generally, toluene, hexane, ethyl acetate, methyl ethyl ketone, heptane or a mixture thereof is used as a diluent. In the emulsion type release agent coating solution, water is generally used as a diluent. Used and adjusted to a coatable viscosity.
If necessary, silica, an antistatic agent, a dye, a pigment and other additives may be added to the silicone-based release agent coating liquid. The silicone release agent coating liquid thus prepared is applied to one surface of the base film by, for example, a gravure coating method, a bar coating method, a multi-roll coating method, or the like. The coating amount is suitably from 0.01 to 3 g / m ² , particularly preferably from 0.03 to 1 g / m ² as the solid content conversion coating amount.
In order to cure the applied coating liquid, either heat treatment in the oven of the coating machine or ultraviolet irradiation after the heat treatment may be used, but the latter is more likely to cause heat shrinkage of the base film. It is desirable in terms of prevention of occurrence, silicone curability, and adhesion of the release agent to the base film.
In addition, when using ultraviolet irradiation together, it is desirable to use the silicone type release agent which added the photoinitiator, or to add a photoinitiator at the time of preparation of a coating liquid. As the photoinitiator to be added at the time of preparing the coating liquid, the same photoinitiator as that described above can be used as a photoinitiator to be added to the silicone release agent as necessary.
In the case of only heat treatment, it is appropriate to heat in the temperature range of about 70 to 160 ° C. for a time until it is sufficiently cured, but in the case of combined use of heating and ultraviolet irradiation, the heating temperature is about 50 to 120 ° C. Can be lowered.
For the ultraviolet irradiation, conventionally known ones such as a high pressure mercury lamp, a metal halide lamp, a high power metal halide lamp, and an electrodeless lamp can be used, but an electrodeless lamp that is excellent in terms of curability of the silicone-based release agent is suitable. is there. The UV output may be selected as appropriate, but is preferably 50 W / cm to 360 W / cm.
The thickness of the silicone release agent layer thus formed is usually about 0.01 to 3 μm, preferably 0.01 to 1 μm.

On the other hand, as the non-silicone release agent, conventionally known ones such as a long chain alkyl group-containing compound system, an alkyd resin system, an olefin resin system, a rubber system, and an acrylic resin system can be used.
Examples of the long-chain alkyl group-containing compound include conventionally known compounds such as polyvinyl carbamate obtained by reacting a polyvinyl alcohol polymer with a long-chain alkyl isocyanate having 8 to 30 carbon atoms, and polyethyleneimine. An alkyl urea derivative obtained by reacting an alkyl isocyanate can be used. In the present invention, the long-chain alkyl group-containing compound thus obtained is preferably a compound having a melting point of 70 ° C. or higher from the viewpoint of the temporal stability of the release performance in the formed release agent layer.
Further, when using a polyvinyl carbamate obtained by reacting a polyvinyl alcohol polymer with a long-chain alkyl isocyanate, there is no particular limitation on the degree of saponification or degree of polymerization of the polyvinyl alcohol polymer, but a complete saponification type Is more advantageous in handling, and those having a polymerization degree of about 300 to 1,700 are generally used.
The coating liquid containing the long-chain alkyl group-containing compound may be either a solvent type or an emulsion type, but is preferably an aqueous emulsion type. Examples of the aqueous emulsion type include those obtained by emulsifying the long-chain alkyl group-containing compound obtained as described above to obtain an aqueous emulsion. There is no restriction | limiting in particular about an emulsification processing method, A general method is employable. For example, an aqueous emulsion can be obtained by stirring and mixing an organic solvent solution of a long-chain alkyl group-containing compound in an aqueous solution of a surfactant and emulsifying, and then removing the organic solvent as necessary. Further, an aqueous emulsion can be obtained by emulsifying and dispersing a long chain alkyl group-containing compound and a surfactant in the presence of water using a pressure kneader, a colloid mill or the like without using an organic solvent.
The release agent layer can be formed by applying and drying the coating solution thus obtained using a general coating apparatus such as a roll coater, a gravure coater, a Meyer bar coater, or a lip coater. .
As drying conditions, it is appropriate to heat for a time until it is sufficiently cured in a temperature range of about 80 to 160 ° C.

As the alkyd resin release agent, an alkyd resin having a crosslinked structure is generally used.
Formation of the alkyd resin layer having a crosslinked structure uses, for example, a method in which a layer comprising a thermosetting resin composition containing (X) an alkyd resin, (Y) a crosslinking agent, and (Z) a curing catalyst as required is heated and cured. Can do.
The alkyd resin as the component (X) is not particularly limited, and can be appropriately selected from conventionally known alkyd resins. This alkyd resin is a resin obtained by a condensation reaction between a polyhydric alcohol and a polybasic acid, and is a non-convertible alkyd which is modified with a condensate of a dibasic acid and a dihydric alcohol or a non-drying oil fatty acid. There are resins and convertible alkyd resins which are condensates of dibasic acids and trivalent or higher alcohols, and any of them can be used in the present invention.
Examples of the polyhydric alcohol used as a raw material of the alkyd resin include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, and neopentyl glycol, glycerin, trimethylolethane, Examples thereof include trihydric alcohols such as trimethylolpropane, and polyhydric alcohols such as diglycerin, triglycerin, pentaerythritol, dipentaerythritol, mannitol, and sorbit. These may be used individually by 1 type and may be used in combination of 2 or more type.

Examples of the polybasic acid include aromatic polybasic acids such as phthalic anhydride, terephthalic acid, isophthalic acid, and trimetic anhydride, aliphatic saturated polybasic acids such as succinic acid, adipic acid, and sebacic acid, maleic acid, Diels such as aliphatic unsaturated polybasic acids such as maleic anhydride, fumaric acid, itaconic acid, citraconic anhydride, cyclopentadiene-maleic anhydride adduct, terpene-maleic anhydride adduct, rosin-maleic anhydride adduct -The polybasic acid by Alder reaction etc. can be mentioned. These may be used individually by 1 type and may be used in combination of 2 or more type.
On the other hand, examples of the modifying agent include octylic acid, lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, eleostearic acid, ricinoleic acid, dehydrated ricinoleic acid, coconut oil, linseed oil, and kili oil. , Castor oil, dehydrated castor oil, soybean oil, safflower oil, and their fatty acids. These may be used individually by 1 type and may be used in combination of 2 or more type.
In the present invention, the alkyd resin of component (X) may be used alone or in combination of two or more.
Examples of the crosslinking agent for the component (Y) include not only amino resins such as melamine resins and urea resins, but also urethane resins, epoxy resins, and phenol resins.
In the present invention, the crosslinking agent of the component (Y) may be used alone or in combination of two or more.
In the said thermosetting resin composition, the ratio of the said (X) component and (Y) component has the preferable range of 70:30 thru | or 10:90 by solid content mass ratio. When the ratio of the component (X) is more than the above range, the cured product cannot obtain a sufficient cross-linked structure, which causes a decrease in peelability. On the other hand, if the proportion of the component (X) is less than the above range, the cured product becomes hard and brittle, and the peelability is lowered. A more preferable ratio of the component (X) to the component (Y) is 65:35 to 10:90 in terms of solid content mass ratio, and a range of 60:40 to 20:80 is particularly preferable.
In the said thermosetting resin composition, an acidic catalyst can be used as a curing catalyst of (Z) component. There is no restriction | limiting in particular as this acidic catalyst, It can select suitably from well-known acidic catalysts conventionally known as a crosslinking reaction catalyst of an alkyd resin. As such an acidic catalyst, for example, an organic acidic catalyst such as p-toluenesulfonic acid and methanesulfonic acid is suitable. This acidic catalyst may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, the usage-amount is 0.1-40 mass parts normally with respect to a total of 100 mass parts of the said (X) component and (Y) component, Preferably it is 0.5-30 mass parts, More preferably, it is 1-1. It is selected in the range of 20 parts by mass.

The alkyd resin-based release agent coating liquid containing the thermosetting resin composition may be either a solvent type or an emulsion type, but a solvent type is preferred from the viewpoint of convenience in use. Examples of the organic solvent used at this time include toluene, xylene, methanol, ethanol, isobutanol, n-butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. These may be used individually by 1 type and may be used in combination of 2 or more type.
In these organic solvents, the (X) component, the (Y) component, and the (Z) component and various additive components used as required are respectively added at a predetermined ratio to adjust the viscosity to be coatable. Thus, an alkyd resin release agent coating solution is obtained. There is no restriction | limiting in particular as an additive component used in this case, From the well-known additive component conventionally known as an additive component of an alkyd resin, it can select suitably and can be used. For example, an antistatic agent such as a cationic surfactant, another resin such as an acrylic resin for adjusting flexibility and viscosity, a leveling agent, an antifoaming agent, a coloring agent, and the like can be used.
The alkyd resin release agent coating solution thus obtained is applied to one surface of the base film, for example, bar coating method, reverse roll coating method, knife coating method, roll knife coating method, gravure coating method, air doctor The release agent layer can be formed by coating by a conventionally known coating method such as a coating method or a doctor blade coating method, followed by heat curing at a temperature of about 80 to 150 ° C. for several tens of seconds to several minutes.

As the olefin resin release agent, a crystalline olefin resin is used. As this crystalline olefin resin, polyethylene, crystalline polypropylene resin, and the like are suitable. Examples of the crystalline polypropylene resin include a propylene homopolymer having an isotactic structure or a syndiotactic structure, and a propylene-α-olefin copolymer. Examples of polyethylene include high-density polyethylene, low-density polyethylene, and linear low-concentration polyethylene. These crystalline olefin resins may be used alone or in combination of two or more.
In the present invention, the olefin resin release agent generally employs an extrusion laminating method, and a release agent layer can be provided on one surface of the substrate film.
Moreover, as a rubber-type release agent, what is shown below can be used, for example.
A release agent using a rubber resin such as a natural rubber resin; a synthetic rubber resin such as butadiene rubber, isoprene rubber, styrene-butadiene rubber, methyl methacrylate-butadiene rubber, and acrylonitrile-butadiene rubber;

As the acrylic release agent, an acrylic resin having a crosslinked structure is generally used.
For example, the release agent layer made of an acrylic resin having a crosslinked structure is formed by heating and curing a layer made of an acrylic resin composition containing a (meth) acrylate copolymer having a crosslinkable functional group and a crosslinking agent. Can be used.
The (meth) acrylic acid ester-based copolymer having a crosslinkable functional group includes a (meth) acrylic acid ester having an alkyl group of 1 to 20 carbon atoms and a functional group having an active hydrogen. The copolymer of a body and the other monomer used depending on necessity can be mentioned preferably.
Here, examples of the (meth) acrylic acid ester having 1 to 20 carbon atoms of the alkyl group in the ester portion include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) Butyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, Examples include dodecyl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.
On the other hand, examples of the monomer having a functional group having active hydrogen include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) (Meth) acrylic acid hydroxyalkyl esters such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate; monomethylaminoethyl (meth) acrylate, (meth) acrylic Monoethylaminoethyl acid, monomethylaminopropyl (meth) acrylate, monoalkylaminoalkyl (meth) acrylate such as monoethylaminopropyl (meth) acrylate; acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid And ethylenically unsaturated carboxylic acids such as citraconic acid. These monomers may be used independently and may be used in combination of 2 or more type.
Examples of other monomers used as desired include vinyl esters such as vinyl acetate and vinyl propionate; olefins such as ethylene, propylene and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; styrene Styrene monomers such as α-methylstyrene; diene monomers such as butadiene, isoprene and chloroprene; nitrile monomers such as acrylonitrile and methacrylonitrile; acrylamide, N-methylacrylamide, N, N- Examples include acrylamides such as dimethylacrylamide. These may be used alone or in combination of two or more.

In the acrylic resin composition, the (meth) acrylic acid ester copolymer used as a resin component preferably has a weight average molecular weight of 300,000 or more. This (meth) acrylic ester copolymer may be used alone or in combination of two or more.
There is no restriction | limiting in particular as a crosslinking agent in this acrylic resin composition, Arbitrary things can be suitably selected and used from what was conventionally used as a crosslinking agent in acrylic resin. Examples of such crosslinking agents include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides, and metal salts. A compound is preferably used. This crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more type. Further, the amount used depends on the kind of the crosslinking agent, but is usually 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic ester copolymer. It is selected in the range of mass parts.
Various additives such as antioxidants, ultraviolet absorbers, light stabilizers, softeners, fillers, colorants and the like are optionally added to the acrylic resin composition as long as the object of the present invention is not impaired. can do.
The coating liquid comprising the acrylic resin composition thus obtained is applied to one surface of the base film, for example, bar coating method, reverse roll coating method, knife coating method, roll knife coating method, gravure coating method. The acrylic release agent layer is formed by coating by a conventionally known coating method such as an air doctor coating method or a doctor blade coating method, and by heat curing at a temperature of about 80 to 120 ° C. for several tens of seconds to several minutes. be able to.

In the release film of the present invention, the thickness of the non-silicone release agent layer formed as described above on one surface of the base film is usually about 0.01 to 3 μm, preferably 0.03 to 1 μm.
In the release film of the present invention, the antistatic layer formed on the base film surface opposite to the release agent layer comprises an active energy ray-curable resin composition containing carbon nanofibers and, if necessary, a conductive polymer compound It is a layer made of a cured product.
In the active energy ray-curable resin composition, an active energy ray-polymerizable monomer and / or oligomer having two or more polymerizable unsaturated groups in the molecule is used as the active energy ray-curable polymerizable compound. Can do.
The active energy ray-curable polymerizable compound refers to a polymerizable compound having energy quanta in an electromagnetic wave or a charged particle beam, that is, a polymerizable compound that is crosslinked and cured by irradiation with ultraviolet rays or an electron beam.
When the active energy ray is an actinic ray such as ultraviolet ray, a photopolymerization initiator is usually used together with the active energy ray polymerizable monomer and / or oligomer. On the other hand, when the active energy ray is an electron beam, the photopolymerization initiator may not be used. In the present invention, it is preferable to use actinic rays such as ultraviolet rays as active energy rays. Therefore, the active energy ray-curable resin composition comprises (A) an active energy ray-polymerizable monomer and / or oligomer having two or more polymerizable unsaturated groups in the molecule, and (B) a light containing a photopolymerization initiator. A curable resin composition is preferred.

In this photocurable resin composition, examples of the active energy ray polymerizable monomer having two or more polymerizable unsaturated groups in the molecule used as the component (A) include 1,4-butanediol di (meta ) Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di ( (Meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) Acrylate, trimer Roll propane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris Examples thereof include polyfunctional acrylates such as (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate. These active energy ray polymerizable monomers may be used alone or in combination of two or more.
On the other hand, the active energy ray polymerizable oligomer includes a radical polymerization type and a cationic polymerization type. Examples of the radical polymerization type active energy ray polymerizable oligomer include a polyester acrylate type, an epoxy acrylate type, a urethane acrylate type, and a polyol acrylate type. Etc.
Here, as the polyester acrylate oligomer, for example, by esterifying hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding alkylene oxide to a polyvalent carboxylic acid with (meth) acrylic acid. The epoxy acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. The urethane acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid. Furthermore, the polyol acrylate oligomer can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid. These active energy ray polymerizable oligomers may be used alone or in combination of two or more.
On the other hand, examples of the cationic polymerization type active energy ray polymerizable oligomer include epoxy, oxetane resin, vinyl ether resin and the like. Here, the epoxy resin is obtained by oxidizing a compound obtained by epoxidizing polyhydric phenols such as bisphenol resin or novolak resin with epichlorohydrin, etc., a linear olefin compound or a cyclic olefin compound with a peroxide or the like. And the like.

  In addition, as the photopolymerization initiator of the component (B), among the active energy ray polymerizable oligomers and monomers, radical polymerization type photopolymerizable oligomers and photopolymerizable monomers include, for example, benzoin and benzoin methyl ether. , Benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy 2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, α-hydroxycyclohexyl phenylmethanone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino Propan-1-one, 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2 -Ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone Examples thereof include dimethyl ketal and p-dimethylamine benzoate. Examples of the photopolymerization initiator for the cationic polymerization type photopolymerizable oligomer include oniums such as aromatic sulfonium ion, aromatic oxosulfonium ion, and aromatic iodonium ion, tetrafluoroborate, hexafluorophosphate, hexafluoroantimony. And compounds composed of anions such as nitrates and hexafluoroarsenates. These may be used singly or in combination of two or more, and the blending amount thereof is usually 0.1 with respect to 100 parts by mass of the photopolymerizable monomer and / or photopolymerizable oligomer. It is selected in the range of 2 to 10 parts by mass.

The carbon nanofiber contained in the active energy ray-curable resin composition is preferably a cylindrical hollow fiber having an average outer diameter of about 0.5 to 120 nm and an average length of about 0.5 μm or more. A carbon nanotube which is a substance is used. When the average outer diameter is less than 0.5 nm, dispersion is difficult, and the conductivity is not sufficiently exhibited. When the average outer diameter exceeds 120 nm, the smoothness is lowered and the conductivity may be lowered. Further, when the average length is less than 0.5 μm, the conductivity tends to decrease, but when the average length is too long, the dispersibility deteriorates. A preferable average outer diameter is 1 to 100 nm, and a preferable average length is 0.8 to 15 μm.
Further, from the viewpoint of the antistatic performance of the antistatic layer, the amorphous carbon particles contained as impurities in the carbon nanotubes are desirably 20% by mass or less.
The carbon nanotube used in the present invention has a shape in which one surface of graphite is wound into a cylindrical shape, and the single-walled carbon nanotube having a structure in which the graphite layer is wound in one layer is wound in two or more layers. Any of multi-walled carbon nanotubes may be used, but multi-walled carbon nanotubes are preferred. The reason why the multi-walled carbon nanotube is preferable is that the multi-walled carbon nanotube can easily achieve both the affinity with the binder resin and the characteristics of the carbon nanotube itself. In order to give carbon nanotubes an affinity for the active energy ray-curable resin composition, surface treatment such as oxidation is required. However, single-walled carbon nanotubes have only one graphite layer, so the surface By the treatment, the crystal arrangement of the graphite layer is broken, and the excellent conductivity and mechanical properties of the carbon nanotube are often lost. In this regard, multi-walled carbon nanotubes having two or more graphite layers are preferred.

The carbon nanotubes used in the present invention are a catalytic chemical vapor deposition method (CCVD method), a vapor deposition method (CVD method), a laser ablation method, a carbon rod / carbon fiber in which iron or a cobalt-based catalyst is introduced into the pores of zeolite. It can manufacture by the arc discharge method etc. which used etc.
The end shape of the carbon nanotube is not necessarily cylindrical, and may be deformed, for example, conical. Further, either a structure in which the end of the carbon nanotube is closed or an open structure can be used, but a structure having an open end is preferable. A carbon nanotube having a closed end can be opened by a chemical treatment such as nitric acid.
In the present invention, the carbon nanotubes have the active energy so that the content in the formed antistatic layer is preferably 0.1 to 30% by mass, more preferably 0.3 to 10% by mass. It is added and dispersed in the linear curable resin composition. If the content of the carbon nanofibers in the antistatic layer is less than 0.1% by mass, the antistatic performance may be insufficient, and if it exceeds 30% by mass, the dispersibility of the carbon nanofibers deteriorates and the antistatic property is prevented. The performance tends to be rather degraded.

There is no particular limitation on the conductive polymer compound contained in the active energy ray-curable resin composition as required, and any one of conventionally known conductive polymer compounds can be appropriately selected and used. be able to. Examples of the conductive polymer compound include polyacetylene-based compounds such as trans-type polyacetylene, cis-type polyacetylene, and polydiacetylene; poly (phenylene) -based materials such as poly (p-phenylene) and poly (m-phenylene); polythiophene, poly ( 3-alkylthiophene), poly (3-thiophene-β-ethanesulfonic acid), polythiophene systems such as a mixture of polyalkylenedioxythiophene and polystyrene sulfonate; polyaniline systems such as polyaniline, polymethylaniline, polymethoxyaniline; polypyrrole Polypyrrole systems such as poly (3-methylpyrrole) and poly-3-octylpyrrole; poly (phenylene vinylene) systems such as poly (p-phenylene vinylene); poly (vinylene sulfide) systems; poly (p-phenylene sulfide) systems; (Chienile Vinylene) compounds, and the like. Of these, polyacetylene-based, polythiophene-based, polyaniline-based, polypyrrole-based, and poly (phenylene vinylene) -based compounds are preferable from the viewpoints of performance and availability.
In the present invention, these conductive polymer compounds may be used alone or in combination of two or more. In addition, the conductive polymer compound has a content in the formed antistatic layer of usually 0.01 to 10% by mass, preferably 0.01, from the viewpoint of improving the antistatic performance and dispersibility. It is added to the active energy ray-curable resin composition so as to be ˜5 mass%, more preferably 0.1 to 3 mass%.
The active energy ray-curable resin composition used in the present invention, preferably the photocurable resin composition, is prepared by mixing the active energy ray-curable polymerizable compound, carbon nanofiber, and conductive polymer compound in a suitable solvent. , Photopolymerization initiators and various optional components as desired, such as monofunctional active energy ray polymerizable monomers, antioxidants, ultraviolet absorbers, light stabilizers, leveling agents, antifoaming agents, colorants, etc. And can be prepared by dissolving or dispersing.
Examples of the monofunctional active energy ray polymerizable monomer include cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, N-vinylpyrrolidone and the like. Is mentioned.
Examples of the solvent used in this case include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, methanol, ethanol, propanol, isopropanol, and butanol. Alcohols, acetone, methyl ethyl ketone, ketones such as 2-pentanone, isophorone, cyclohexanone, esters such as ethyl acetate and butyl acetate, ether solvents such as ethyl cellosolve, glycol ether solvents such as ethylene glycol monoethyl ether, etc. .
The concentration and viscosity of the composition thus prepared are not particularly limited as long as they can be coated, and can be appropriately selected according to the situation.

Next, on the surface of the base film opposite to the release agent layer, the composition is applied to a conventionally known method such as a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, or a gravure. An antistatic layer is formed by coating with a coating method or the like to form a coating film, and optionally heating and drying, and then irradiating this with active energy rays to cure the coating film. .
As the active energy ray, for example, actinic rays such as ultraviolet rays are preferably exemplified. The ultraviolet rays are obtained with a high-pressure mercury lamp, a fusion H lamp, a xenon lamp or the like, and the irradiation amount is usually 100 to 500 mJ / cm ² .
The thickness of the antistatic layer formed in this manner is usually about 0.01 to 3 μm, preferably 0.01 to 1 μm, more preferably about 0.1 to 3 μm from the viewpoint of balance between antistatic performance and economy. It is 03-0.5 micrometer.
The surface resistivity of the antistatic layer is 10 ¹³ Ω / □ or less, preferably 10 ¹⁰ Ω / □ or less.
In the present invention, an active energy ray-curable resin composition containing carbon nanofibers is applied to one surface of a base film, dried to provide a coating, and then the coating is irradiated with active energy rays. There is also provided a method for producing a release film which is cured to form an antistatic layer, and on the other side, a coating solution containing a release agent is applied and dried to form a release agent layer.
The release film of the present invention is provided with a release agent layer on one side of a base film and an antistatic layer containing carbon nanofibers and optionally a conductive polymer compound on the back side, and has an excellent antistatic function. And has a peeling function. This release film is suitable as, for example, a cast film forming process film such as polyurethane resin, polyacrylic resin or polyvinyl chloride resin, a green film forming process film for laminated ceramic capacitors, or a protective film for an adhesive in an adhesive product. Used for.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the performance of the peeling film obtained in each example was calculated | required according to the method shown below.
(1) Surface resistivity Samples obtained by cutting the release films prepared in Examples and Comparative Examples to 100 mm × 100 mm size were conditioned at 23 ° C. and 50% RH for 24 hours, and then the surface of the antistatic layer of the samples The surface resistivity was measured according to JIS K 6911.
(2) Release force An adhesive tape [manufactured by Nitto Denko Corporation, trade name “31B tape”] was bonded to the release agent layer of the release film prepared in Examples and Comparative Examples. Next, after conditioning for 24 hours under conditions of 23 ° C. and 50% RH, the film is cut into a length of 150 mm and a width of 20 mm, and the release film side is peeled off at a speed of 0.3 m / min at an angle of 180 ° using a tensile tester. It peeled and the force (peeling force) required for peeling was measured.
(3) Smoothness Based on JIS B 0601, the arithmetic average roughness Ra of the surface of the antistatic layer was measured using “SURFPAK-SV” manufactured by MITUTOYO.

Reference example 1
Contains 75 parts by mass of an acrylic monomer containing dipentaerythritol hexaacrylate, pentaerythritol hexaacrylate and N-vinylpyrrolidone in a mass ratio of 45:20:10, 20 parts by mass of butyl acetate and 30 parts by mass of isopropanol. 125 parts by mass of solution, 15.5 parts by mass of an aqueous solution containing a conductive polymer of polyethylene dioxythiophene polystyrene sulfonate (PEDT / PSS) at a ratio of 1.3% by mass, photoinitiation of α-hydroxycyclohexylphenylmethanone 0.2 parts by mass of the agent was mixed. Further, a photocurable resin composition diluted with isopropanol was prepared so that the total amount of the acrylic monomer and the conductive polymer was 1% by mass.
Carbon nanofibers having an average diameter of 15 nm and an average length of 1 μm (trade name “CNF-T”, tube shape, 3% by mass isopropanol dispersion type) with an average diameter of 15 nm and an average length of the above photocurable resin composition were added to the total solid content ( The coating solution I was prepared by adding so that the content in the antistatic layer was 1% by mass.
Next, the coating liquid I is 0.05 μm in thickness after drying on a polyethylene terephthalate (PET) film [Mitsubishi Chemical Polyester Film Co., Ltd., trade name “T-100”] having a thickness of 38 μm. So that it was evenly coated with a Meyer bar. Next, it was heated for 1 minute in a dryer at 55 ° C, and immediately irradiated with ultraviolet light at a conveyor speed of 10 m / min. did.
On the other hand, 100 parts by mass of thermosetting silicone [manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KS-847H”] and 1 part by mass of a curing agent [manufactured by Shin-Etsu Chemical Co., Ltd., trade name “CAT-PL-50T”] were diluted with toluene. A coating liquid II having a solid content of 1.1% by mass was prepared.
Next, this coating solution II was uniformly applied to the back surface of the PET film provided with the antistatic layer so that the thickness after drying was 0.1 μm, and the coating solution was dried at 130 ° C. for 1 minute. A release agent layer was formed by drying to produce a release film.
The performance of this release film is shown in Table 1.
Reference example 2
As a photocurable resin composition, a conductive polymer aqueous solution (PEDT / PSS), a photoinitiator (α-hydroxycyclohexylphenylmethanone), a solution containing an acrylic oligomer and a monomer (dipentaerythritol hexaacrylate, pentaerythritol) Hexaacrylate, N-vinylpyrrolidone), a photo-curing coating agent [trade name “EL Coat 515” manufactured by Idemitsu Technofine Co., Ltd.] consisting of ethylene glycol monoethyl ether and isopropanol which dissolves them to 1% by mass with isopropanol. A release film was produced in the same manner as in Reference Example 1 except that the diluted one was used.
The performance of this release film is shown in Table 1.
Reference example 3
A release film was prepared in the same manner as in Reference Example 2 except that the thickness of the antistatic layer was changed to 0.1 μm in Reference Example 2, and its performance was evaluated. The results are shown in Table 1.
Example 4
In Reference Example 2, a release film was prepared in the same manner as in Reference Example 2 except that the release agent layer was formed as described below, and its performance was evaluated. The results are shown in Table 1.
A mixture of stearyl-modified alkyd resin and methylated melamine [manufactured by Hitachi Chemical Co., Ltd., trade name “Tesfine 303”] and 3 parts by mass of p-toluenesulfonic acid were added to toluene, and the solid content concentration was 2 parts by mass. Coating liquid II was prepared and applied, and dried at 140 ° C. for 1 minute to form a release agent layer.
Example 5
In Example 4, a release film was produced in the same manner as in Example 4 except that the thickness of the antistatic layer was changed to 0.1 μm, and its performance was evaluated. The results are shown in Table 1.
Comparative Example 3
In the preparation of the coating liquid I in Reference Example 1, a conductive polymer aqueous solution was not used, and carbon nanofibers were used so that the content in the total solid content (antistatic layer) was 10% by mass. Produced a release film in the same manner as in Reference Example 1 and evaluated its performance. The results are shown in Table 1.
Comparative Example 1
In Reference Example 1, a release film was prepared in the same manner as in Reference Example 1 except that the antistatic layer was not formed, and its performance was evaluated. The results are shown in Table 1.
Comparative Example 2
In Example 4, a release film was produced in the same manner as in Example 4 except that the antistatic layer was not formed, and the performance was evaluated. The results are shown in Table 1.

  The release film of the present invention has a release agent layer on one side of a base film and an antistatic layer having an antistatic layer on the back side, and has an excellent antistatic function and a release function. It is suitably used as a process film for cast film formation such as a resin or a polyvinyl chloride resin, a process film for green sheet molding of a multilayer ceramic capacitor, or a protective film for an adhesive in an adhesive product.

Claims (5)

Carbon nanofibers having an average length of 0.8 to 15 μm and an average outer diameter of 1 to 100 nm, a conductive polymer compound, an ultraviolet polymerizable monomer or oligomer having two or more polymerizable unsaturated groups in the molecule, and a photoinitiator A coating solution I containing a silicone-based release agent obtained by adding a crosslinking agent and a catalyst to a thermosetting silicone resin, and preparing a coating liquid II on one side of the base film, The coating liquid I is applied and dried, and then the coating film is irradiated with ultraviolet rays to be cured. The content of the carbon nanofibers in the cured product is 0.1 to 30% by mass, While forming an antistatic layer having a conductive polymer compound content of 0.01 to 10% by weight and a thickness of 0.01 to 3 μm, coating liquid II is converted to solid content on the other surface. As coating amount, 0.01-3 g / m ² A method for producing a release film, characterized by forming a release agent layer having a thickness of 0.01 to 3 μm by irradiating with ultraviolet rays after applying heat treatment at a heating temperature of 50 to 120 ° C. after coating. The method for producing a release film according to claim 1, wherein the thermosetting silicone resin is polydimethylsiloxane having a vinyl group or a hexenyl group as a functional group. Carbon nanofibers having an average length of 0.8 to 15 μm and an average outer diameter of 1 to 100 nm, a conductive polymer compound, an ultraviolet polymerizable monomer or oligomer having two or more polymerizable unsaturated groups in the molecule, and a photoinitiator A coating liquid I containing alkyd resin-based release agent, a long-chain alkyl group-containing compound-based release agent, and one or more release agents selected from acrylic resin-based release agents and a crosslinking agent are used in a mass ratio. The coating liquid II contained at 70:30 to 10:90 is prepared, the coating liquid I is applied to one side of the substrate film, dried, and then the coating film is irradiated with ultraviolet rays to be cured. The thickness of the carbon nanofiber in the cured product is 0.1 to 30% by mass, and the content of the conductive polymer compound in the cured product is 0.01 to 10% by mass. In addition to forming a 0.01 to 3 μm antistatic layer, etc. A method for producing a release film, comprising: applying a coating liquid II to the surface, followed by heat treatment to form a release agent layer having a thickness of 0.01 to 3 μm. Conductive polymer compounds are polyacetylene, polythiophene, polyaniline, polypyrrole, poly (phenylene vinylene), poly (vinylene sulfide), poly (p-phenylene sulfide), and poly (thienylene vinylene) compounds. The method for producing a release film according to any one of claims 1 to 3, wherein the method is at least one selected from the group consisting of : The surface resistivity of the antistatic layer, the production method of the release film according to any one of claims 1-4 is ¹⁰ 10 Ω / □ or less.